• International Journal of Highway Engineering
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• v.12 no.3
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• pp.79-85
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• 2010

This paper presents a preliminary study of roller types for chip seals based on aggregate retention performance. Chip seal test sections composed of single seals of granite 78M aggregate and CRS-2 emulsion were constructed using three different roller types: the pneumatic tire roller, steel wheel roller, and combination roller. In order to investigate the performance of these rollers effectively, it is critical to test chip seal samples obtained directly from field construction. Therefore, test sections were constructed on New Sandy Hill Church Road near Bailey, North Carolina. Chip seal samples obtained from these sections were used for laboratory testing. The aggregate retention performance was evaluated using the flip-over test (FOT), Vialit test, and the third-scale Model Mobile Loading Simulator (MMLS3). Based on the test results and visual observation, both the pneumatic roller and the combination roller used together are recommended to improve chip seal performance with the sequence of the pneumatic roller rolling first followed by the combination roller.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1275-1280
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• 2004

This paper presents the construction of an active suspension system of a one-wheel car model by using fuzzy reasoning. The car model is approximately described by a nonlinear two degrees freedom system subject to excitation from a road profile, and the active control force is constructed by actuating a pneumatic actuator, and the degradation of the performance due to the delay of the pneumatic actuator is improved by inserting a compensator. The fuzzy control is obtained by single input rule modules fuzzy reasoning, and the excitation from the road profile is estimated by using a disturbance observer. The experimental result shows that the proposed active suspension system much improves the performance in the vibration suppression of the car model.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.413-418
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• 2000

For Pneumatic system control, we need a data transmission system with high speed and high realibility for information interchange between main computer and solenoid valves and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid valves. In addition we developed a communication protocol for construction of RS-485 based multidrop network, and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. The field test results show that, even under high noise environment, the data transmission of 375Kbps rate is possible up to 1,000m without using repeater. In addition, the system developed in this research is proved to be used easily for extension of a communication network because of its module structure.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1152-1157
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• 2005

This paper is concerned with the construction of an improved sliding mode control for the active suspension system of a one-wheel car model subject to the excitation from a road profile. The active control is composed of the equivalent and the switching controls where an improved sliding surface is proposed. The active control force is generated by operating a pneumatic actuator due to the control signal that constructed by measuring the state variables of the car model and by estimating the excitation from the road profile using the VSS observer. The experimental result indicates that the proposed active suspension system is relatively effective in the vibration suppression of the car model.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.2-150
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• 2001

For pneumatic system control, we need a data transmission system with high speed and reliability for information interchange between main computer and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid valves. In addition, we developed a communication protocol for construction of RS-485 based multi-drop network, and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. The field test results show that, even under high noise environment, the data transmission of 375Kbps rate is ...

• Journal of Drive and Control
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• v.9 no.1
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• pp.18-24
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• 2012

The paper deals with the design of a new low-friction seal for a pneumatic cylinder with high speed actuation. The seal performance with variation of the cross sections in piston seals with elastomeric material was investigated to minimize the friction forces using ABAQUS. The contact stress and strain distributions and frictional forces of the piston seals were investigated with variation of interference fits, supply pressures and friction coefficients. To develop adequate and productive procedures, the finite element models of the piston seals were created and nonlinear analysis of a seal design was conducted in order to build further knowledge and understanding of the seal's performance characteristics.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.93-97
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• 2010

Wheel skids may occur during train operations due to low adhesion at the wheel-rail contact point abnormally, and the skids, in turn, result in flats appearing on the wheels, which affect safety and ride comfort significantly. Thus, anti-skid control has a crucial role for safe braking and prevention from flats that could cause a disastrous train accident. This paper presents simulation studies on an anti-skid control unit (ASCU) with a brake system of a rolling stock including a pneumatic model for brake power supply and dump valve operation.

• Journal of Drive and Control
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• v.10 no.4
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• pp.29-33
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• 2013

Pneumatic system is widely applied in various industry because it have a many advantage(low cost, high safety, etc..). For design of pneumatic system, accurate flow measurement is required. In this study, compressible fluid flow measurement apparatus was designed and built. It uses an isothermal chamber that can approximate isothermal condition. Therefore, it can be measured for flow-rate using pressure response of isothermal chamber. As a result, this apparatus can be measured for sonic conductance and critical pressure ratio of pneumatic components and it required less time and energy than conventional flow meter. The effectiveness of the designed apparatus is proved by experimental result.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1152-1156
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• 2003

For pneumatic valve system control, we need a serial data transmission system with high speed and reliability for information interchange between main computer and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic valve system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid control valves. in addition, we developed a communication protocol for construction of rs-485 based multi-drop network and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. the field test results show that, even under high noise environment, the data transmission of 375kbps rate is possible up to 1,500meter without using repeater. In addition, the system developed in this research is easily to be extended for a communication network because of its modular structure.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.865-870
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• 2001

For pneumatic system control, we need a data transmission system with high speed and high reliability or information interchange between main computer and solenoid valves and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid valves. In addition we developed a communication protocol for construction of RS-485 based multidrop network, and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. The field test results show that, even under high noise environment, the data transmission of 375Kbps rate is possible up to 1,000m without using repeater. In addition, the system developed in this research is proved to be used easily for extension of a communication network because of its module structure.